Viscosity-increased oat base and fermented oat base product

Abstract

A method of producing a viscosity-increased non-dairy food product, comprising providing a mixture of a deamidated oat base and a plant-based protein isolate, cross-linking glutamine units and lysine units of the protein isolate and oat proteins contained in the oat base by a transglutaminase enzyme, and fermenting the mixture by a yogurt, sour cream or cheese starter culture. Also disclosed are products obtainable by the method and uses thereof.

Description

TECHNICAL FIELD

[0001] The present invention relates to a viscosity-increased oat base and products made thereof, such as non-dairy yoghurt. The invention also relates to the corresponding manufacturing process. BACKGROUND

[0002] Oat beverages ("oat milk") are known in the art for use as milk replacers (EP 731646 A1 ; US 5686123; US 6451369A) and as raw material for other non-dairy dairy products. For various reasons, many consumers prefer oat beverages, for example because they contain the health-beneficial soluble beta-glucan fiber, they do not contain potentially allergy-inducing proteins and lactose which cannot be digested by the majority of the world's population.

[0003] In the existing oat milk production process, the starting material, such as oat flour or oat bran, is heated to a certain temperature for a period of time which is sufficient to fully prevent the development of endogenous enzyme activities, in particular lipase / lipoxygenase activity, but also beta-glucanase activity. The oat milk known in the art can also be referred to as "oat base" because, in addition to its use as a beverage, in particular a milk beverage, it can also be used as a production base for other food products, such as oat yoghurt, oat cream or oat paste, or as a food additive.

[0004] Due to the low fat content in oat milk (typically 0.5 wt%), it is often added in the form of vegetable oil (such as rapeseed oil) to the product.

[0005] Oat base or oat milk can be used to prepare oat beverages by adding sugar, flavorings, fruit extracts, etc. The taste, texture and viscosity of these beverages are expected to be similar to the corresponding beverages prepared from milk. This is not a problem with respect to low-viscosity beverages, that is to say, similar to the viscosity of milk. However, problems arise when using oat base to prepare products corresponding to viscosity-increased milk products, such as yoghurt or sour cream. Viscosity-increased milk products such as yoghurt or sour cream are prepared by fermentation using cultures of Lactobacillus delbrueckii subspecies, bulgaricus and thermophilus, or in combination with other lactic acid bacteria and bifidobacteria. The lactic acid formed in this process lowers the pH, causing the milk proteins to coagulate, thereby significantly increasing the viscosity of the product.

[0006] The protein content of oat base and milk is about 1 wt% and about 3.5 wt%, respectively.

[0007] WO 2014 / 123466 A1 discloses a deamidated liquid oat base and a process for its preparation.

[0008] Lactoprotein cross-linking and / or modifying enzymes such as transglutaminase, laccase, tyrosinase, peroxidase, sulfhydryl oxidase and protein glutaminase are used in the dairy industry to stabilize the structure of milk-based products. WO 2007 / 060288 Al discloses a method for the manufacture of sour fresh dairy products by the combined use of transglutaminase, enzyme-activating compounds with oxidizing or reducing properties such as yeast extract and glutathione, and acidifying agents in the form of microbial starter cultures, chemical acidifying agents and mixtures thereof, which enables to compensate for the viscosity loss in the production of yoghurt when using milk with low protein content. WO 2013 / 064736 Al discloses a liquid enzyme preparation comprising a polyol-water suspension of a lactoprotein cross-linking and / or modifying enzyme such as transglutaminase.

[0009] Object of the invention

[0010] It is an object of the present invention to provide a viscosity significantly increased oat beverage or base of the above kind.

[0011] It is a further object of the present invention to provide a viscosity increased product obtainable from the oat base or beverage by fermentation.

[0012] It is a further object of the present invention to provide a corresponding method.

[0013] Further objects of the present invention will become apparent from the following description of preferred embodiments thereof given for the purpose of description and not limitation, and from the appended claims. SUMMARY

[0014] According to the present invention, a modified aqueous oat base or beverage, hereinafter referred to as a "modified oat base" of the above kind with a viscosity significantly increased, is provided. The viscosity of the modified oat base is obtained enzymatically.

[0015] According to an important aspect of the present invention, the viscosity of the modified oat base is not obtained by the addition of one or more viscosity modifying agents or thickening agents, i.e. agents forming highly viscous aqueous solutions, such as xanthan gum, sodium alginate, hydroxypropyl methylcellulose, carrageenan, agar agar, gelatin, etc.

[0016] The term oat base as used herein relates to an aqueous liquid oat product of low viscosity and with a high maltose content, which is obtained or obtainable from oats by treatment with starch degrading enzymes such as alpha- and / or beta-amylase. The term oat beverage as used herein relates to a ready-to-drink pasteurized oat base, which can comprise additives not significantly influencing its viscosity, such as sodium chloride, vegetable oil (such as e.g. rapeseed oil), sweeteners, vitamins and flavorings.

[0017] The viscosity-increased oat base or beverage of the present invention is obtained by cross-linking oat proteins, which consist of an oat base or beverage supplemented with a plant protein isolate, in particular a denatured plant protein isolate.

[0018] According to the present invention, the protein consisting of the oat base or beverage supplemented with the protein is cross-linked by a transglutaminase.

[0019] According to a further important aspect of the present invention, the oat base is a deamidated oat base. According to a preferred aspect of the present invention, the deamidation is carried out in the presence of calcium carbonate.

[0020] According to a further preferred aspect of the present invention, the added plant protein isolate consists of or comprises a denatured plant protein isolate, in particular a heat denatured plant protein.

[0021] Preferred plant protein isolates according to the present invention include pea protein isolate, potato protein isolate, broad bean protein isolate, chickpea protein isolate, lentil protein isolate, in particular pea protein isolate.

[0022] According to the present invention, a method for producing a viscosity-increased non-dairy product is disclosed, comprising providing a mixture of a deamidated oat base or beverage and a plant protein isolate, in particular a denatured plant protein isolate; cross-linking glutamine units and lysine units of the plant protein isolate by a transglutaminase. Prior to the addition of the transglutaminase, the mixture of the deamidated oat base or beverage is preferably heated to a temperature of 80°C or higher.

[0023] In particular, according to the present application, a method of producing a viscosity- increased oat base is disclosed, comprising: providing an aqueous oat base or beverage, optionally comprising a viscosity promoter; providing a native plant protein isolate and / or a denatured plant protein isolate; combining the aqueous oat base or beverage with the plant protein isolate; heating the combination of the aqueous oat base or beverage and the plant protein isolate to a temperature of 80°C or above and holding it at that temperature for a time sufficient to form a combination of the aqueous oat base or beverage and the heat-treated plant protein isolate; bringing the temperature of the combination of the aqueous oat base or beverage and the heat-treated plant protein isolate to between 35°C and 65°C; adding to the combination of the aqueous oat base or beverage and the heat-treated plant protein isolate a protein cross-linking amount of transglutaminase, while keeping said mixture at said temperature of between 35°C and 65°C for a time required for a 2-fold or more increase in viscosity, in particular for a 5-fold or more increase in viscosity, to form a viscosity-increased oat base or beverage; inactivating the transglutaminase by heating the viscosity-increased oat base or beverage to a temperature of 80°C or more, in particular 90°C or more; cooling the viscosity-increased oat base or beverage to one of: room temperature or, if longer storage is required, below room temperature, or to a temperature suitable for further processing; with the proviso that protease activity is excluded from the process.

[0024] The present application also discloses a viscosity-increased oat base or beverage obtainable by the method of the present application, as well as the use of the oat base or beverage as a food, a food additive or a starting material for the production of a food, all for human consumption, in particular for the production of yoghurt, sour cream and fresh cheese.

[0025] The present application is based on the insight that the plant protein isolate is preferably used in denatured form and is additionally denatured by heat treatment during the process. The most preferred plant protein isolate is a pea protein isolate, in particular in denatured form.

[0026] The preferred amount of added plant protein is from 0.5 wt% or 1 wt% to 2 wt% or more, for example to 3 wt% or more, even up to 4 wt% or 5 wt% or 7 wt% or more.

[0027] The preferred aqueous oat base of the present application has a dry matter content of 7-15 wt%, preferably about 10 wt%, the dry matter of the oat base comprising 10 wt% to 50 wt% maltose or a mixture of maltose and glucose, 30 wt% to 80 wt% by weight of maltodextrin.

[0028] Preferred heat treatment conditions include a combination of an inactivation temperature of 80°C or higher, in particular 90°C or higher, in particular about 95°C, and an inactivation period of from 5 minutes to 60 minutes, in particular 10 minutes to 30 minutes.

[0029] The viscosity of dairy yoghurt is about 2000 Pa-s (stirred yoghurt) to about 5000 Pa-s (Greek and Turkish yoghurt). The method of the present application increases the viscosity by a factor of 2 or 5 or more, even by a factor of 10 or more, for example to a viscosity of 10000 Pa-s or more, even 20000 or more, which is comparable to the viscosity of a curd. In contrast, the viscosity of the corresponding fermentation product obtained in the method of the present application by omitting the protein cross-linking is below 1000, typically in the range of 50 Pa-s to 500 Pa-s.

[0030] Preferred vegetable protein isolates contain a combination of about 14 wt% or more, more preferably 15 wt% or more, such as about 17 wt% and even up to 20 wt% glutamine / glutamic acid, and about 5 wt% or more, more preferably about 6 wt% or more, such as about 7 wt% or 8 wt% lysine. Pisum sativum L. protein, such as pea protein isolate, is the most preferred protein for use in the method. Pea protein significantly increases the viscosity more than other vegetable proteins investigated, such as lentil, fava bean, potato, hemp, rapeseed oil and oat protein. Preferred vegetable proteins have an isoelectric point of about 4.0 to about 5.0, in particular about 4.2 to 4.6, most preferably about 4.4.

[0031] The preferred amount of added transglutaminase is 0.1 U / g to 5 U / g, in particular 0.2 U / g to 2 U / g, most preferably about 1 U / g.

[0032] In addition to increasing the viscosity, the method of the present application also increases the elastic modulus, for example from below 100 Pa to 500 Pa or 1000 Pa or more.

[0033] Furthermore, the product of the method of the present application has a higher yield point, in particular a yield point that is 1.5 or 2 or more times higher, the yield point being the point of strain at which the gel network breaks. Thus, the method of the present application provides a product with improved gel properties, i.e. a stronger gel.

[0034] The viscosity enhancer of the present application is a viscosity enhancer that does not increase or only does not significantly increase (such as by a factor of less than 1.5 or less than 1.2 or 1.1) the viscosity of an aqueous medium in which it is dissolved at a concentration of up to 5 wt%. A preferred viscosity enhancer is calcium carbonate. Another preferred viscosity enhancer is a combination of magnesium carbonate and calcium carbonate.

[0035] The cereal oat suspension is preferably heated to a temperature of about 50 °C to about 75 °C to cross-link the proteins for a time sufficient to produce an oat base of the desired composition while controlling its viscosity by varying the amount and / or kind of plant protein added and / or the amount of transglutaminase.

[0036] According to the present application, this control is also possible by using a combination of plant proteins from different sources, such as, for example, a combination of pea protein isolate, potato protein isolate, broad bean protein isolate, chickpea protein isolate, lentil protein isolate.

[0037] The viscosity-increased oat base or beverage of the present application and the products made therefrom differ from the oat bases of the prior art and the corresponding products made therefrom in that the viscosity is significantly increased. In the process of the present application, the use of transglutaminase has no or only an insignificant effect on the taste of the product.

[0038] According to a preferred aspect, the viscosity-increased oat base or beverage of the present application can be used for the production of non-dairy cheese.

[0039] According to the present application, the viscosity-increased oat base or beverage produced by the process of the present application can be used as a starting material in a fermentation process for the production of fermented non-dairy products, such as yogurts and cheeses, which process comprises: subjecting the viscosity-increased oat base or beverage to a fermentation temperature of about 35 °C to about 50 °C, in particular about 43 °C; adding a fermentation starter culture, in particular a yogurt or cheese fermentation starter culture; maintaining the viscosity-increased cereal suspension or oat base at the fermentation temperature for a period of time sufficient to form a fermented product, in particular a non-dairy yogurt-like or cheese-like product, such as, for example, 8 hours to 24 hours, in particular 12 hours to 15 hours or to 18 hours.

[0040] According to a preferred aspect of the present application, a small amount of sugar, such as 0.2 wt% or 0.5 wt% or 0.7 wt% and up to 1 wt% of dry matter, is added at the beginning or during the yogurt culture food incubation. According to another preferred aspect of the present application, a buffer is added at the beginning or during to stabilize the pH, in particular at a pH of less than 6.0, in particular less than 5.0, most preferably at about 4.5.

[0041] During the fermentation process, the cereal suspension is preferably not agitated by stirring to jeopardize the gel properties of the product.

[0042] Furthermore, according to the present invention, a method for producing a fermented non-dairy product with increased viscosity is disclosed, comprising: providing an oat-based material or beverage optionally containing a viscosity promoter and having deamidated groups; providing a natural and / or denatured plant-based protein isolate; mixing the oat-based material or beverage and the protein isolate; heating the mixture of the oat-based material or beverage and the protein isolate to a temperature of 80°C or higher, particularly 90°C or higher, most preferably about 95°C, for 5 to 60 minutes, particularly 10 to 30 minutes; cooling the mixture; adding glutamine transferase and a fermentation culture to the mixture; maintaining the mixture including the glutamine transferase and the fermentation culture at a fermentation temperature, such as at a temperature of 35°C to 50°C, particularly about 43°C, for a period of time sufficient to form a fermentation product (particularly a yogurt-like or curd-like product), such as 8 to 24 hours, particularly 12 to 15 hours or 18 hours; optionally destroying the enzyme activity by heating the fermentation product; and cooling the fermentation product to room temperature or lower.

[0043] According to a preferred aspect of the invention, the pH of the method of the invention is controlled prior to incubation with glutamine transferase by adjusting and / or maintaining the pH of the mixture of deamidated oat substrate and plant protein isolate at a pH significantly higher than the isoelectric point of the plant protein isolate, for example, by 1.0 pH unit higher, especially by 1.5 pH unit or 2.0 pH unit or more.

[0044] Preferred fermented products that can be obtained by this method are non-dairy yogurt, non-dairy sour cream, and non-dairy fresh cheese.

[0045] The invention will be described in more detail below with reference to some preferred embodiments thereof.

[0046] Description of preferred embodiments

[0047] Materials and Methods

[0048] Oat kernels: Remove the skin, steam treat, and wet or dry grind.

[0049] oat bran (Frebaco Kvarn AB, Sweden: Swedish oat grains, processed by steaming, are milled in a rolling mill. Composition (wt%): Protein 18%, Fat 7%, Carbohydrates 45%, Fiber 16wt%, Water 9.5%.

[0050] Enzymes: Glutaminant transferase, α-amylase, β-amylase, and yogurt and fresh cheese products, such as sour cream, quark cheese, and cream cheese, are available from various commercial sources, such as Danisco DuPont (Yomix™, Denmark) and Christian Hansen (YoFlex).TM eXact TM ; Denmark). Before use, the transglutaminase and the yogurt culture were dissolved in tap water (15 U / g and 0.001-0.2 g / g, respectively).

[0051] Alpha-amylase activity: one Ceralpha unit is defined as the amount of enzyme needed to release 1 micromole of p-nitrophenol from BPNPG7 (a non-reducing end-blocked p-nitrophenyl malt heptoside) in 1 minute under the prescribed test conditions: http: / / secure.megazyme.com / files / BOOKLET / K-BETA3_1010_DATA.pdf

[0052] Beta-amylase activity: one BNPbeta-G3 (p-nitrophenyl-beta-D-maltotrioside) unit is defined as the amount of enzyme needed to release 1 micromole of p-nitrophenol from PNPbeta-G3 in 1 minute under the prescribed test conditions: http: / / secure.megazyme.com / files / BOOKLET / K-BETA3_1010_DATA.pdf.

[0053] Transglutaminase activity: determined by the hydroxamic acid method. One unit corresponds to the amount of enzyme that produces 1 micromole of hydroxamic acid per minute at pH 6.0.

[0054] Viscosity: measured with Kinexus Pro+, Malvern Instruments, UK; http: / / www.malvern.com / en / products / product-range / kinexus-range / kinexus-pro-plus / .

[0055] Example 1. Method for producing a viscosity-improved oat base of the invention from a state-of-the-art oat base

[0056] Materials: oat base produced according to EP 1124441 A1 containing about 1 wt% oat protein to which rapeseed oil was added to increase the total fat content to about 3 wt%; transglutaminase ACTIVA TG-WM (100 U / g), Ajinomoto (Japan); pea protein, Nutralys S85F and F85F (Roquette, France) containing about 80 wt% protein; YoMix 511 yogurt culture, Danisco DuPont (Denmark); rapeseed oil (AAK, Sweden); granulated sugar. Water solutions for addition during fermentation were prepared: a) 15 U / g transglutaminase solution, b) 1.8 wt% YoMix TM TM TM 511 yogurt culture, Danisco DuPont (Denmark); rapeseed oil (AAK, Sweden); granulated sugar. Water solutions for addition during fermentation were prepared: a) 15 U / g transglutaminase solution, b) 1.8 wt% YoMix​​TM 511 solution.

[0057] Pea protein (3.8 g) was added to 94 g of the oat base in a glass flask and the mixture was shaken to disperse the protein. The flask was immersed in a boiling water bath at 95 °C and kept at this temperature for 10 minutes, then cooled to room temperature by immersing it in cold water. This mixture was used as the starting material.

[0058] First method of the invention: simultaneous cross-linking and fermentation. The following components were mixed with the starting material: 265 μΐ of transglutaminase solution (1 U / g protein); 340 μΐ of YoMix solution (0.0006%); 1.15 g of rapeseed oil (to give a total fat content of about 4 wt%); 0.69 g of sugar. The mixture was shaken to mix and dissolve the components, then kept in a water bath at 43 °C overnight. The reaction was terminated by boiling the reaction mixture in a microwave oven, then shaking and reheating to bring the reaction mixture to the boil. The mixture was cooled and stored in the refrigerator for analysis.

[0059] Second method of the invention: sequential cross-linking and fermentation. To the starting material (about 100 g) was added a transglutaminase solution (265 μΐ, 1 U / g protein). The mixture was stored in a water bath at 50 °C for 3 hours, and stirred once an hour. The reaction was terminated by boiling the reaction mixture in a microwave oven, then shaking and reheating to bring the reaction mixture to the boil in the oven. The cooled product was a viscosity-increased oat base or oat beverage of the invention. It could be used as such, for example, as a food product or in the manufacture of food products or fermented. If fermented, the following reagents were added to the cooled viscosity-increased oat base or oat beverage: 340 μΐ of YoMix solution (0.006%); 1.15 g of rapeseed oil to give a total fat content of about 4 wt%; 0.69 g of sugar (0.69 wt%); however, it is also within the scope of the invention to add the rapeseed oil and / or the sugar at an earlier stage of the process. The mixture was incubated in a water bath at 43 °C overnight. The non-dairy yoghurt thus produced was cooled and stored in the refrigerator for analysis.

[0060] Example 2. Cross-linking effect of different protein isolates

[0061] Some plant protein isolates were included to show their cross-linking properties in the deamidated oat base at a total protein content of 4 wt%. The results were confirmed by rheological measurements, as shown in Table 1 (sequential cross-linking and fermentation) and Table 2 (simultaneous cross-linking and fermentation). The zero-shear viscosity of the oat base without added protein isolate was about 50 Pa-s, the elastic modulus (G') was about 5 Pa, and the yield point was about 1.

[0062] Table 1. Cross-linking of fermentation products of compositions of protein isolate and deamidated oat base by transglutaminase, sequential cross-linking and fermentation

[0063] Protein isolate added to 4% of total protein content Viscosity Pa-s Elastic modulus Pa' Yield point Pea (Nutralys S85F) 2 000 300 0.9 Chickpea (FCPP40) 3 000 200 1.1 Pea (Pisane C9) combined with deamidated oat beverage 8 000 800 1

[0064] Table 2. Cross-linking of fermentation products of compositions of protein isolate and deamidated oat base by transglutaminase, simultaneous cross-linking and fermentation

[0065]

[0066]

[0067] Example 3. Cross-linking effect of different starting materials

[0068] An important factor for the cross-linking properties is the nature of the protein isolate, as shown in Example 2. Another important factor is whether the protein isolate is heat treated before cross-linking, as shown in Table 3. However, the effect of heat treatment seems not to be of general nature, but is limited to certain protein isolates, for example pea protein isolate. According to the present application, the properties of the resulting gel or curd can be adjusted by varying the time and / or temperature of heat treatment. Higher temperatures and / or longer treatment periods result in an increased viscosity and gel strength.

[0069] The inclusion of deamidated oat base or oat beverage and the addition of viscosity promoting agents are additional factors influencing the cross-linking properties and viscosity. Compositions of oat base and pea protein, which were not heat treated before transglutaminase incubation, did not thicken, whereas heat treatment resulted in a slight increase in viscosity.

[0070] Table 3. Cross-linking of fermentation products of compositions of heat treated (10 min, 95°C) and non-heat treated protein isolate and deamidated oat beverage by transglutaminase, sequential / simultaneous cross-linking and fermentation

[0071]

[0072] Without heat treatment, the same treatment applied to compositions of deamidated oat beverage and pea protein resulted in a slightly thickened gel, whereas heat treatment provided a strong gel or curd. The effect of deamidated oat beverage was confirmed by rheological measurements, as shown in Table 4. The inclusion of calcium carbonate (corresponding to a calcium content of about 120 mg / 100 ml) as viscosity promoting agent for the oat base increased the viscosity and provided an even stronger gel or curd.

[0073] Table 4. Cross-linking of fermentation products of compositions of pea protein isolate and oat beverage by transglutaminase, sequential / simultaneous cross-linking and fermentation

[0074]

[0075] Example 4

[0076] Adjusting the pH to / and keeping the pH at a pH value substantially different from the isoelectric point during incubation with transglutaminase increases viscosity and provides a stronger gel or curd.

[0077] The isoelectric point of the plant protein isolate is at about pH 4.5; the isoelectric point of the pea protein isolate is at about pH 4.4. Table 5 illustrates the increase in viscosity after adjusting the pH of the oat beverage containing pea protein isolate to pH 6.5 and 7.5 before incubation with transglutaminase and fermentation. The pH was adjusted with aqueous sodium hydroxide and hydrochloric acid.

[0078] Table 5. Cross-linking effect of transglutaminase on the fermentation product with adjusted pH to a pH value substantially different from the isoelectric point, sequential cross-linking and fermentation

[0079]

Claims

1. A method of producing a viscosity-increased aqueous liquid oat product comprising providing a mixture of an aqueous deamidated oat base or beverage and a plant protein isolate; cross-linking glutamine units and lysine units of the protein isolate by transglutaminase, wherein the plant protein isolate comprises or consists of: pea protein isolate, potato protein isolate, lentil protein isolate, chickpea protein isolate, lentil protein isolate, and wherein the plant protein isolate is added in an amount that increases the total protein content of the oat base or beverage to 2-5 wt%.

2. The method of claim 1, wherein the mixture is heated to a temperature of 80°C or more before the addition of transglutaminase.

3. The method of claim 1, wherein the added plant protein isolate consists of or comprises denatured plant protein.

4. The method of claim 1, comprising: The pH of the mixture is adjusted and / or maintained at a pH value that is higher than the isoelectric point of the plant protein isolate by 1.0 pH units, or 1.5 pH units, or 2.0 pH units or more, before incubation with transglutaminase.

5. The method of claim 1, further comprising: a) providing an oat base or beverage, optionally comprising a viscosity promoter; b) providing a native plant protein isolate and / or a denatured plant protein isolate; c) combining the oat base or beverage and the plant protein isolate; d) heating the combination of oat base or beverage and plant protein isolate to a temperature of 80°C or more and maintaining at that temperature for a time sufficient to form a combination of oat base or beverage and heat-treated plant protein isolate; e) bringing the temperature of the combination of oat base or beverage and heat-treated plant protein isolate to 35-65°C; f) adding to the combination of oat base or beverage and heat-treated plant protein isolate a protein-cross-linking amount of transglutaminase while maintaining the mixture at the 35-65°C temperature for a time required to increase the viscosity by a factor of 2 or more to form a viscosity-increased oat base or beverage; g) inactivating the transglutaminase by heating the viscosity-increased oat base or beverage to a temperature of 80°C or more; h) cooling the viscosity-increased oat base or beverage to one of: room temperature or, if longer storage is required, below room temperature, or to a temperature suitable for further processing; with the proviso that protease activity is excluded from the method.

6. The method of claim 5, wherein the oat base or beverage is a deamidated oat base or beverage.

7. The method of claim 5 or 6, wherein the plant protein isolate is a pea protein isolate or comprises a pea protein isolate.

8. The method of claim 5 or 6, wherein the pea protein isolate is a denatured pea protein isolate or comprises a denatured pea protein isolate.

9. The method of claim 5, wherein the viscosity-increased oat base or beverage has a dry matter content of 8 wt% to 15 wt%.

10. The method of claim 9, wherein the viscosity-increased oat base or beverage dry matter comprises 10 wt% to 50 wt% maltose or a mixture of maltose and glucose, 30 wt% to 80 wt% maltodextrin.

11. The method of claim 5, wherein the inactivation is for a period of 5 min to 60 min, and wherein the inactivation is at a temperature of 80 °C to 95 °C.

12. The method of claim 5, wherein the viscosity-increased oat base or beverage has a viscosity of 2000 Pa-s or more.

13. The method of claim 5, wherein the viscosity-increased oat base or beverage has an elastic modulus of 100 Pa to 500 Pa.

14. The method of claim 5, wherein the viscosity-increased oat base or beverage has a yield point that is 1.5 or 2 times or more greater than a corresponding non-increased oat base or beverage.

15. The method of claim 5, wherein the viscosity-increasing agent is calcium carbonate.

16. The method of claim 5, comprising adjusting and / or maintaining the pH of the mixture to a pH value that is 1.0 pH units, or 1.5 pH units, or 2.0 pH units or more above the isoelectric point of the plant protein isolate prior to and / or during incubation with transglutaminase.

17. A viscosity-increased oat base or beverage obtained according to the method of any one of claims 5-16.

18. Use of a viscosity-increased oat base or beverage obtained or obtainable according to the method of any one of claims 5-16 as any food, food additive or starting material for the production of food intended for human consumption.

19. The use of claim 18 for the production of a fermented food product yogurt, sour cream or fresh cheese.

20. A method of fermenting the viscosity-increased oat base or beverage of claim 17, comprising: a) bringing the oat base or beverage to a fermentation temperature of 35 °C to 50 °C; b) adding a fermentation starter culture to the viscosity-increased oat base or beverage; c) maintaining the viscosity-increased oat base or beverage at the fermentation temperature for a period of time sufficient to form a fermented product, the period of time being 8 h to 24 h.

21. A fermented food product obtainable according to the method of claim 20 in the form of a plant yogurt, sour cream or fresh cheese having a viscosity of 2000 Pa-s or more.

22. A fermented food product obtainable according to the method of claim 20 in the form of a plant curd having a viscosity of more than 5000 Pa-s.

23. The method of claim 20, wherein, The method obtains a fermented food product having an elastic modulus of 100 Pa to 500 Pa.

24. A method of producing a viscosity-increased non-dairy fermented food product from a deamidated oat base or beverage, comprising: a) providing an aqueous deamidated oat base or beverage, optionally including a viscosity-increasing agent; b) providing a plant protein isolate or a denatured plant protein isolate; c) mixing the deamidated oat base or beverage and the protein isolate; d) heating the mixture of step c) to a temperature of 80 °C or higher for 5 min to 60 min; e) cooling the mixture; f) adding glutamine transaminase and a yogurt or cheese starter culture to the mixture; g) maintaining the mixture at a fermentation temperature of 35 °C to 50 °C for a period of time sufficient to form a fermented product, the period of time being 8 h to 24 h; h) optionally destroying enzyme activity by heating the fermented product; i) cooling the fermented product to room temperature or lower, wherein the plant protein isolate comprises or consists of a pea protein isolate, a potato protein isolate, a horse bean protein isolate, a chickpea protein isolate, a lentil protein isolate, and wherein the plant protein isolate is added in an amount that increases the total protein content of the oat base or beverage to 2 wt% - 5 wt%.

25. The method of claim 24, wherein the plant protein isolate optionally comprises or consists of a denatured plant protein isolate.

26. The method of claim 24, comprising: The pH of the mixture is adjusted and / or maintained at a pH value that is higher than the isoelectric point of the plant protein isolate by 1.0 pH units prior to and / or during incubation with glutamine transaminase and a yogurt or cheese starter culture.

27. The method of claim 24, wherein the viscosity promoter is calcium carbonate.

28. The method of claim 24, wherein the fermented food product is a non-dairy yogurt, a non-dairy sour cream, or a non-dairy fresh cheese.

29. A fermented food product obtainable according to the method of any one of claims 24-28, having a viscosity of 2000 Pa s or higher.

30. The fermented food product of claim 29, having an elastic modulus of 100 Pa to 500 Pa.

31. The fermented food product of claim 29, being in the form of a non-dairy yogurt, a non-dairy sour cream, or a non-dairy fresh cheese or curd.

Images